In many areas of machine, plant and automotive engineering, rotational irregularities occur when rotational movements are transmitted. These rotational irregularities can result, for example, when a rotational movement of this type is coupled into a shaft or also due to changes in the amount of energy or torque taken from the shaft and the rotational movement of the shaft.
An example of this is drivetrains of motor vehicles, i.e., for example, drivetrains of passenger cars, trucks or other utility vehicles, in which an internal combustion engine is used as drive motor. Because of its principle of operation, an engine of this kind often has discontinuous torque peaks which are coupled into its crankshaft or into another corresponding shaft and can possibly lead to deviations with respect to a timing of the torque and/or speed. Rotational irregularities of this kind can manifest themselves as vibration components of a rotational movement, for example.
Vibration dampers are used to keep such rotational irregularities or vibration components of a rotational movement away from other components of a complex mechanical system like a drivetrain of a motor vehicle. These vibration dampers are intended to eliminate the vibration components or at least reduce the amplitude thereof. Thus, for example, in a drivetrain of a motor vehicle within the framework of a start-up element which is typically integrated between the internal combustion engine and a downstream transmission in order to allow continued running of the internal combustion engine also when the vehicle is stopped, during which the transmission input shaft is likewise stationary.
Energy accumulator elements are often employed in vibration dampers. These energy accumulator elements allow temporary absorption and, therefore, buffering of energy peaks of the rotational movement which are then coupled into the rotational movement again at a later time. In many torsional vibration dampers, the energy accumulators which are often configured as spring elements are connected in the actual torque path, i.e., the path of rotational movement, such that the rotational movement is transferred via the energy accumulator elements.
In contrast, in tuned mass vibration dampers no transmission of rotational movement takes place via the energy accumulator elements. These tuned mass vibration dampers typically comprise one or more damper masses which can carry out oscillations in a force field to damp an unwanted vibration component of the rotational movement. The force field is formed by the forces acting on the damper masses. In particular, these forces also include a centrifugal force in addition to the weight force.
Sharply diverging requirements are sometimes imposed on corresponding tuned mass vibration dampers and the components making up the latter. Foremost in this respect, apart from functioning as efficiently as possible, are, for example, available installation space, a production in the simplest possible manner and lowest possible noise nuisance, to name only a few aspects. The components surrounding the tuned mass vibration damper typically allow only a limited installation space to be taken up by the tuned mass vibration damper in all operating states. It should also be producible in the simplest possible manner. Noise can also occur in tuned mass vibration dampers because of operation, for example, due to changes in the forces acting on the damper masses. As a result of the latter, it can happen that the damper masses of the tuned mass vibration damper are no longer guided with respect to the movement thereof substantially by centrifugal forces, but rather by the weight force acting upon them, for example, when a speed of the rotational movement and, therefore, the influence of the centrifugal forces decreases. Noises can occur when the damper masses collide with each other or with other components, for example, with the ends of their guide paths.
These noises, which are frequently metallic, can be perceived by the driver and the passengers of the motor vehicle as well as outside of the motor vehicle. These noises are frequently perceived by persons as annoying because the occurrence of these metallic noises is unexpected. For this reason, developers have tried to reduce noise generation in a tuned mass vibration damper.
DE 10 2011 100 895 A1 is directed to a centrifugal pendulum absorber with a pendulum flange that is rotatable around an axis of rotation and with a plurality of pendulum masses distributed along the circumference on both sides of the pendulum flange. Two axially opposed pendulum masses are connected to one another in each instance by connection means extending through the pendulum flange to form pairs of pendulum masses. In order to achieve an elastic limiting of the pendulum masses without resorting to stop bumpers and cutouts made for the latter in the pendulum flange, an elastic limiting of an oscillating movement of the pendulum masses is carried out in this case by means of an annular spring that is integrated radially inside of the pendulum masses.
U.S. Pat. No. 6,382,050 relates to a vibration damping device with a deflection mass arrangement which is arranged at a base body which is rotatable around an axis of rotation having at least one deflection mass and a deflection path which is associated with the at least one deflection mass and along which the deflection mass can move during the rotation of the base body around the axis of rotation. The deflection path has a vertex area, deflection areas on both sides of the vertex area, the distance of these deflection areas from the axis of rotation decreasing from the vertex area to the end areas of the deflection areas, and a braking arrangement which is operative in the end areas of the deflection areas and by means of which the movement of the at least one deflection mass can be gradually decelerated when approaching or reaching a respective end region of a deflection path.
This should be carried out through the simplest possible constructional means so as to facilitate as far as possible not only the availability of the necessary component parts but also the assembly thereof in the form of the tuned mass vibration damper and the components comprising the latter.
Therefore, there is a need for a better compromise between a functioning of a tuned mass vibration damper, an efficient utilization of installation space, reduced noise and the simplest possible production of a tuned mass vibration damper.